openvswitch: fix potential out of bound access in parse_ct
[ Upstream commit 69ec932e364b1ba9c3a2085fe96b76c8a3f71e7c ]
Before the 'type' is validated, we shouldn't use it to fetch the
ovs_ct_attr_lens's minlen and maxlen, else, out of bound access
may happen.
Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 48386bf..b28e45b 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1088,8 +1088,8 @@ static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
nla_for_each_nested(a, attr, rem) {
int type = nla_type(a);
- int maxlen = ovs_ct_attr_lens[type].maxlen;
- int minlen = ovs_ct_attr_lens[type].minlen;
+ int maxlen;
+ int minlen;
if (type > OVS_CT_ATTR_MAX) {
OVS_NLERR(log,
@@ -1097,6 +1097,9 @@ static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
type, OVS_CT_ATTR_MAX);
return -EINVAL;
}
+
+ maxlen = ovs_ct_attr_lens[type].maxlen;
+ minlen = ovs_ct_attr_lens[type].minlen;
if (nla_len(a) < minlen || nla_len(a) > maxlen) {
OVS_NLERR(log,
"Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",